exam 1 Flashcards
consider two sounds, one has a really high frequency (5000Hz), the other has a really low frequency (50Hz). Based on the information provided, which wave characteristic will be different between these two sounds?
period
which wave characteristic is wavelength most closely related to?
period
a wave has a period of 0.004807s. what is the waves frequency?
208 Hz (1/period)
consider the image above. which letter corresponds with an example of constructive interference?
A
Consider the sound produced by two hands clapping. In an open field the duration of a clap is 22ms (0.022s). However, in the enclosed stairwell of the Human Sciences and Services building a clap lasts much longer; 250ms (0.250s). What causes the clap in the stairwell to last such a long time?
the sound is reflecting off the walls
when a sound is generated, for instance by two hands clapping together, what is the best description for how the sound travels from the hands to your ears.
the air molecules in the medium stay mostly in the same place, but begin to oscillate in simple harmonic motion when the pressure wave reaches them
Consider a pendulum, like a washer on a string. Before it is displaced and begins to oscillate in simple harmonic motion, it’s state can be described best by which law of motion?
newtons first law
(DISPLACED, OSCILLATE)
When a sound moves from one medium to another (for example from air to water) what change is most likely to occur?
the wavelength will change
A complex periodic wave has a fundamental frequency of 150Hz. What are the frequencies of this wave’s first three harmonics?
300Hz, 450Hz, 600Hz
An anechoic chamber is a special room with foam baffles on all surfaces (see picture). It is a room designed because of boundary behaviors and interference. They do this to avoid sound interference patterns from echoing sound waves. Hearing scientists use rooms like this to test hearing aids. What boundary behavior are the scientists trying to cause in an anechoic chamber?
absorption
how do earplugs work to reduce sound energy?
the soft squishy material absorbs much of the energy as the wave travels through the ear plug
Consider a pendulum, like a washer on a string. During simple harmonic motion as the pendulum moves it moves past rest position. Which law best describes why it moves past rest position?
newtons first law
(PAST REST POSITION)
Consider a pendulum, like a washer on a string. During simple harmonic motion as the pendulum moves past rest position it eventually stops, changes direction and moves back towards rest position. Which law best describes the phenomenon?
hooke’s law
(STOPS, CHANGE DIRECTION, MOVES TO REST POSITION)
Consider a pendulum, like a washer on a string. During simple harmonic motion the oscillation does not continue forever; it eventually stops moving. Which law best describes this phenomenon?
newtons third law
(STOPS MOVING)
red and blue waves picture
deconstructive interference
